Dispensing apparatus

ABSTRACT

A dispensing apparatus includes: a dish mounting portion having a mounting surface mounted with a dish having a bottom surface and a side surface surrounding the bottom surface; a syringe, arranged above the dish mounting portion, having a nozzle configured to discharge liquid toward an interior of the dish; and a first driving portion configured to change the syringe in direction with respect to a first axis as a center, wherein the first axis is orthogonal to a normal to the mounting surface of the dish mounting portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to Japanese PatentApplication No. 2011-155925, filed Jul. 14, 2011, of which full contentsare incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a dispensing apparatus.

2. Description of the Related Art

A dispensing apparatus configured to discharge liquid from a nozzleusing a syringe, etc., has been used for various purposes.

For example, Japanese Patent Application Laid-open Publication No.2009-291103 discloses an automatic cell culture apparatus including adispensing apparatus (pipette device) to be used in a pipettingoperation applied to a dish (or culture container).

Here, for example, when a cell is cultivated in a dish or a cell ispassaged, operations are performed such as an operation of replacing amedium in a dish with a new medium, an operation of recovering a mediumfrom a dish after cell cultivation is finished, an operation ofrecovering cell, an operation of isolating cells and an operation ofadjusting a colony to a predetermined size. When these operations areperformed, such considerations are required that an old culture media,reagent, and cell suspension are efficiently recovered as well as a newmedium and reagent are promptly spread over an entire cell culturesurface.

However, for instance, as illustrated in FIG. 11, in related dispensingapparatuses, peripheral portions in an inner bottom surface of a dishinclude areas on which liquid discharged from a nozzle of a syringe isunable to be poured directly. Therefore, there is such a problem thatcells remains in areas on which discharged liquid cannot be poureddirectly. There is also another problem that cells such as a lightlyattached cell, which is nearly detached by detachment solution such astrypsin, and a cell, which is deposited on and adhered to a bottomsurface of a dish, cannot be recovered without directly pouring liquidto the cells for a predetermined period of time with a predeterminedflow rate.

When liquid is discharged from a nozzle by tilting a dish as illustratedin FIG. 11A, since the nozzle of a syringe is directed in a verticaldirection and the nozzle therefore interferes with a side surface of thetilted dish, liquid discharged from the nozzle cannot be directly pouredto an area in the vicinity of the uppermost part (area illustrated asR1) out of an area of circumference of an inner bottom surface of adish. Further, since liquid discharged from the nozzle is promptlyaccumulated in an area in the vicinity of the lowermost part (areaillustrated as R2) out of an area of circumference of an inner bottomsurface of a dish, it is also impossible to directly pour liquiddischarged from a nozzle onto the area.

Furthermore, when liquid is discharged from a nozzle by tilting a dishas illustrated in FIG. 11B, since the nozzle of a syringe is directed ina vertical direction and the nozzle therefore interferes with a sidesurface of the dish, as in the case of the area R1, it is impossible todirectly pour liquid discharged from a nozzle to areas in the vicinityof the areas intermediate between the uppermost part and the lowermostpart (areas illustrated as R3 and R4) out of an area of circumference ofan inner bottom surface of the dish.

SUMMARY OF THE INVENTION

In order to achieve the above described object, a dispensing apparatusaccording to an aspect of the present invention, includes: a dishmounting portion having a mounting surface mounted with a dish having abottom surface and a side surface surrounding the bottom surface; asyringe, arranged above the dish mounting portion, having a nozzleconfigured to discharge liquid toward an interior of the dish; and afirst driving portion configured to change the syringe in direction withrespect to a first axis as a center, wherein the first axis isorthogonal to a normal to the mounting surface of the dish mountingportion.

Other features of the present invention will become apparent fromdescriptions of this specification and of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For more thorough understanding of the present invention and advantagesthereof, the following description should be read in conjunction withthe accompanying drawings, in which:

FIG. 1 is an entire configuration diagram of a dispensing apparatusaccording to an embodiment of the present invention;

FIG. 2 is a block diagram illustrating a configuration of a dispensingmechanism included in the dispensing apparatus according to anembodiment of the present invention;

FIG. 3 is a diagram illustrating a first driving mechanism, a thirddriving mechanism and a fourth driving mechanism according to anembodiment of the present invention;

FIG. 4 is a diagram illustrating a second driving mechanism according toan embodiment of the present invention;

FIG. 5 is a diagram illustrating a fifth driving mechanism according toan embodiment of the present invention;

FIG. 6 is a block diagram illustrating a control unit according to anembodiment of the present invention;

FIG. 7 is a diagram describing an example of operations of filling,dispensing, sucking and discharging liquid using a dispensing apparatusaccording to an embodiment of the present invention;

FIG. 8 is a flowchart describing a flow of controlling a dispensingapparatus according to an embodiment of the present invention;

FIG. 9 is a diagram describing control of a dispensing apparatusaccording to an embodiment of the present invention;

FIG. 10A is a diagram describing control of a dispensing apparatusaccording to an embodiment of the present invention;

FIG. 10B is a diagram describing control of a dispensing apparatusaccording to an embodiment of the present invention;

FIG. 11A is a diagram describing areas on which liquid discharged from anozzle of a syringe is not directly poured in a dish; and

FIG. 11B is a diagram describing areas on which liquid discharged from anozzle of a syringe is not directly poured in a dish.

DETAILED DESCRIPTION OF THE INVENTION

At least the following details will become apparent from descriptions ofthis specification and of the accompanying drawings.

Configuration of Dispensing Apparatus

A configuration of a dispensing apparatus 100 according to an embodimentof the present invention will be described with reference to FIG. 1.

FIG. 1 depicts a configuration of cell culture equipment as an exampleof the application of a dispensing apparatus 100 including a dispensingmechanism 101 according to an embodiment of the present invention. Thedispensing apparatus (or cell culture equipment) 100 as illustrated inFIG. 1 is configured including: a syringe 1 for dispensing liquid; and adish mounting portion 22 which is arranged relatively lower than thesyringe 1 and is capable of mounting a dish 5 configured to containliquid to be dispensed, and further including a driving portion 8configured to move the syringe 1 and the dish mounting portion 22. Thedriving portion 8 is configured including a syringe driving portion 3configured to move the syringe 1 and a dish driving portion 4 configuredto move the dish mounting portion 22.

The syringe 1 includes a nozzle 11 configured to discharge liquid.

The dish 5 is a cell culture dish which is formed including a circularbottom surface and a side surface surrounding the circumference of thebottom surface, for example, and is made of resin, for example.

Liquid includes a culture medium for cultivating cells in the dish 5,for example, as well as trypsin and PBS (Phosphate Buffered Saline), forexample, depending on purposes.

The dish mounting portion 22 has a flat dish mounting surface 23 in acircular shape to be matched with the circular dish 5, and includespositioning means 24 by which the center of an inner bottom surface ofthe dish 5 and the center of the dish mounting surface 23 coincide witheach other when the dish 5 is mounted and prevented from easilydeviating from each other.

The syringe driving portion 3 is capable of controlling the position andthe posture of the syringe 1. This enables control of a dischargingdirection of liquid which is to be discharged from the nozzle 11 of thesyringe 1.

The dish driving portion 4 is capable of controlling the position,posture and further rotation of the dish mounting portion 22.

Then, by control of the syringe driving portion 3 and the dish drivingportion 4, the relative position between the nozzle 11 of the syringe 1and the dish 5 is controlled, thereby being able to relatively move thenozzle 11 of the syringe 1 to a position at which liquid is dispensedtoward the dish 5.

Configuration of Dispensing Apparatus

A configuration of the dispensing mechanism 101 included in thedispensing apparatus 100 according to an embodiment of the presentinvention will be described with reference to FIG. 2.

The dispensing mechanism 101 as illustrated in FIG. 2 is configuredincluding the syringe 1, a control unit 2, a filter 12, pumps P1 and P2and valves V1 and V2. The control unit 2 is configured to output controlsignals Sp1 and Sp2 as well as Sv1 and Sv2 for controlling the pumps andthe valves, respectively.

The pump P1 is a pump for discharging configured to introduce theexternal air into the syringe 1 and generate a pressure to dischargeliquid retained in the syringe 1 via the nozzle 11. The pump P2 is apump for sucking configured to discharge the gas (air) retained in thesyringe 1 and generate a pressure (negative pressure) to sucking liquidinto the syringe 1 via the nozzle 11.

The valve V1 is connected so as to open/close a passage between thesyringe 1 and the pump P1 (i.e., first passage). The valve V2 isconnected so as to open/close a passage between the syringe 1 and thepump P2 (i.e., second passage). As each of the valves, a solenoid valve(i.e., electromagnetic valve), a motor-operated pinch valve, etc., forexample, that are controllable by a control signal can be used.

The first and the second passages are merged and diverged at one pointand the filter 12 such as membrane filter is inserted to a passagebetween the merging/diverging point and the syringe 1 in order toprevent liquid retained in the syringe 1 from being contaminated bygetting mixed with unwanted bacteria. Passages between the external airand the pumps P1 and P2 may also be merged/diverged as appropriate.

Configuration of Driving Portion

Subsequently, a configuration of the driving portion 8 will be describedwith reference to FIG. 3 to FIG. 5.

FIG. 3 is a side view of the dispensing apparatus 100. FIG. 4 is a frontview of the dispensing apparatus 100. FIG. 5 is a top surface view ofthe dispensing apparatus 100.

The syringe driving portion 3 includes a first driving mechanism 31, asecond driving mechanism 32 and a third driving mechanism 33. The dishdriving portion 4 includes a fourth driving mechanism 34 and a fifthdriving mechanism 35.

The first driving mechanism 31 includes a first servo motor 51 in theinterior thereof, and as illustrated in FIG. 3, is capable of changing adirection of the nozzle 11 of the syringe 1 with respect to a firstrotation axis parallel to a Y axis as the center. The first rotationaxis is also orthogonal to a normal (perpendicular line) with respect tothe dish mounting surface 23. The direction of the nozzle 11 of thesyringe 1 is changed to the direction of a depression angle (firstdirection) by driving the first servo motor 51. For simplicity ofdescription, the directions in which the nozzle 11 of the syringe 1 ischanged by the first servo motor 51 are also referred to as up and downdirections.

The second driving mechanism 32 includes a second servo motor 52 in theinterior thereof, and as illustrated in FIG. 4, is capable of changingthe direction of the nozzle 11 of the syringe 1 in a plane, which isdetermined by the direction of the Y axis and the direction of thenozzle 11 of the syringe 1, with respect to a second rotation axisperpendicular to the plane as the center. In an embodiment of thepresent invention, the second rotation axis is orthogonal to the normalwith respect to the dish mounting surface 23 and perpendicular to thefirst rotation axis, and thus directions of the nozzle 11 to be changedby the second driving mechanism 32 are directions (i.e., seconddirection) orthogonal to the above described depression angle direction(first direction). For simplicity of description, the directionsorthogonal to the depression angle direction are also referred to asleft and right directions.

The third driving mechanism 33 includes a third servo motor 53 in aninterior thereof, and as illustrated in FIG. 3, is capable of slidingand moving the entire syringe 11 in the direction of the Z axis(vertical direction). The third driving mechanism 33 is configuredincluding a crank structure as illustrated in FIG. 3, wherein an endportion of a first rod 36, configured to be rotationally moved by thethird servo motor 53 with respect to a third rotation axis parallel tothe Y axis as the center, is connected one end of a second rod 37, andthe other end of the second rod is connected to the first drivingmechanism 31, the second driving mechanism 32 and the syringe 1. Thisenables the movement of the syringe 1 in directions toward and away fromthe dish mounting portion 22.

The fourth driving mechanism 34 includes a fourth servo motor 54 in theinternal thereof, and as illustrated in FIG. 3, is capable of changingthe inner bottom surface of the dish 5, which is mounted on the dishmounting portion 22, from a horizontal state to a state where it istilted toward the syringe 1 by rotationally moving the dish mountingportion 22 with respect to a fourth rotation axis (dish first axis)parallel to the Y axis as the center.

The fifth driving mechanism 35 includes a fifth servo motor 55 in theinterior thereof, and as illustrated in FIG. 5, is capable of rotatingthe dish mounting portion 22 with respect to a fifth rotation axis (dishsecond axis) vertical to the dish mounting surface 23 of the dishmounting portion 22 as the center. In an embodiment of the presentinvention, since the fifth rotation axis runs through the center of thedish mounting surface 23, the dish mounting portion 22 is rotated withrespect to the fifth rotation axis as the center, thereby being able torotate the dish 5 mounted on the dish mounting portion 22 using thecenter of the bottom surface of the dish 5 as an axis of rotation. Thefifth driving mechanism 35 is capable of driving to rotate it in a rangeof ±180 degrees, for example, using the fifth rotation axis as thecenter as illustrated in FIG. 5.

The fifth rotation axis of the fifth driving mechanism 35 is arranged sothat the fifth rotation axis and the second rotation axis of the seconddriving mechanism 32 intersect in the same plane. Then, all of the firstrotation axis of the first driving mechanism 31, the third rotation axisof the third driving mechanism 33 and the fourth rotation axis of thefourth driving mechanism 34 are arranged so as to be orthogonal to thisplane.

Therefore, the dish mounting portion 22 is tilted toward the syringe 1by the fourth driving mechanism 34 as well as the direction of thenozzle 11 of the syringe 1 is moved in the up and down directions by thefirst driving mechanism 31, thereby being able to direct the nozzle 11of the syringe 1 so as to be perpendicular to the center of the bottomsurface of the dish 5 mounted on the dish mounting portion 22.

It is also possible to change the direction of the nozzle 11 of thesyringe 1 in the depression angle direction (up and down directions,first direction), that is, the first direction in which two opposingpoints in areas, in which the inner bottom surface of the dish 5 is incontact with the inner side surface thereof, are connected, by furtherdriving the first driving mechanism 31 based on the direction, in whicha normal extends from the nozzle 11 of the syringe 1 to the center ofthe bottom surface of the dish 5 when the nozzle 11 of the syringe 1 isdirected perpendicularly to the center of the bottom surface.

It is also possible to change the direction of the nozzle 11 of thesyringe 1 in a direction intersecting with the depression angledirection (left and right directions, second direction) by furtherdriving the second driving mechanism 32 based on the direction in whichthe normal extends from the nozzle 11 of the syringe 1 to the center ofthe bottom surface of the dish 5 when the nozzle 11 is directedperpendicularly to the center of the bottom surface.

Then, it is possible to direct the nozzle 11 of the syringe 1 over theentire surface on the inner bottom surface of the dish 5 by combinationof the first driving mechanism 31 and the second driving mechanism 32.

For instance, the nozzle 11 of the syringe 1 can be directed to thepredetermined position in a ring-shaped area in which the inner bottomsurface of the dish 5 is in contact with the inner side surface thereof(e.g., position in the vicinity of the uppermost part of the innerbottom surface of the tilted dish 5 in the ring-shaped area), and thenozzle 11 of the syringe 1 can be further changed in direction so as tobe directed along the ring-shaped area.

It is also possible to direct the nozzle 11 of the syringe 1 not only tothe ring-shaped area but also to arbitrary positions on the inner bottomsurface of the dish 5, and thus the direction of the nozzle 11 of thesyringe 1 can be changed along the predetermined route on the innerbottom surface of the dish 5, for example.

It should be noted that each of the first to fifth driving mechanisms 31to 35 includes a rotary potentiometer, for example, which is capable ofdetecting a rotational angle of each of the first to fifth rotation axesand position detecting means configured with an origin sensor and arotary encoder, etc. This enables accurate position control of thesyringe 1 and the dish mounting portion 22 performed by the first tofifth driving mechanisms 31 to 35.

Furthermore, an end position of the nozzle at the time of dispensing isset at a position at which the nozzle is not in contact with the bottomsurface of the dish 5 as well as dispensed liquid does not splash towardthe outside of the dish 5 considering the dispensing flow rate and themoving speed of a nozzle tip.

Configuration of Control Unit

As illustrated in FIG. 6, the dispensing apparatus 100 according to anembodiment of the present invention includes the control unit 2, astorage unit 41, the servo motors 51 to 55, the pumps P1 and P2, thevalves V1 and V2. The control unit 2 is connected to a touch panel 42and a display 43.

The touch panel 42 and the display 43 may be realized as constituents ofthe dispensing apparatus 100 or may also be realized by using anexternal control device such as personal computer connected to thecontrol unit 2 in a communicable manner.

The control unit 2 is a device configured to control operations of theentire dispensing apparatus 100. The control unit 2 includes amicrocomputer capable of executing programs stored in the storage unit41, for example.

The storage unit 41 is configured to store programs to be executed bythe control unit 2 as well as control data and tables to be referred towhen the control unit 2 executes the programs.

The touch panel 42 is a device configured to be used by an operator ofthe dispensing apparatus 100 in order to input various kinds ofinstructions to the dispensing apparatus 100 such as operation start andoperation stop. The operator also inputs, from the touch panel 42,target positions of the syringe 1 and the dish mounting portion 22,positional information of each of the rotation axes of the first tofifth driving mechanisms 31 to 35, or the like, at the initial settingand/or resetting of the dispensing apparatus 100, etc., for example,thereby being able to perform an accurate dispensing operation accordingto the length of the syringe 1 and the size of the dish 5, etc.

The display 43 is a device configured to output a control state of thedispensing apparatus 100 and various kinds of warnings and the like tothe operator of the dispensing apparatus 100.

The control unit 2 is configured to control the servo motors 51 to 55,the pumps P1 and P2 and the valves V1 and V2 by executing programsstored in the storage unit 41 based on the instruction inputted from thetouch panel 42.

Operational Example of Dispensing Apparatus

Subsequently, an operation of the dispensing apparatus 100 according toan embodiment of the present invention will be described with referenceto FIG. 7 to FIG. 10, by giving an example of a series of operations torecover adherent cells, which have been detached by a detachmentsolution such as trypsin, and floating cells using a medium.

FIG. 7 depicts an outline of an operation to recover cells from the dish5 using the dispensing apparatus 100 according to an embodiment of thepresent invention. FIG. 8 exemplifies a flow of controlling thedispensing apparatus 100 when cells are recovered from the dish 5.

In FIG. 7, firstly, the dispensing apparatus 100 sucks liquid, such asmedium solution, stored in a reservoir 6 which is provided at apredetermined location in the vicinity of the dispensing apparatus 100,into the syringe 1 (filling operation). The dispensing apparatus 100then discharges liquid retained in the syringe 1 to the dish 5 (i.e.dispensing operation). The dispensing apparatus 100 then sucks liquidcontaining cells in the dish 5 into the syringe 1 (i.e. suckingoperation) and the liquid retained in the syringe 1 is discharged to astorage tank 7 which is placed at a predetermined location in thevicinity of the dispensing apparatus 100, (i.e. discharging operation).That is, cells are recovered.

Since the filling operation and the sucking operation are the sameoperation in terms of taking in liquid into the syringe 1, the pumps P1and P2 and the valves V1 and V2 operate in the same manner. However, thefilling operation is an operation to take in liquid from the reservoir 6into the syringe 1, whereas the sucking operation is different in thatliquid is taken in from the dish 5 into the syringe 1, and thereforethese operations are described separately for convenience ofexplanation.

Of course, in addition to the above operations, the dispensing apparatus100 is also able to suck liquid from the dish 5 so as to discharge theliquid in the reservoir 6, suck liquid from the dish 5 so as todischarge the liquid in the dish 5, and suck liquid from the reservoir 6so as to discharge the liquid in the reservoir 6. It is also possible tosuck liquid from the reservoir 6 so as to discharge the liquid in thestorage tank 7.

In the following description, in any case, positions to which thesyringe 1 should be moved in order to perform the filling operation, thedispensing operation, the sucking operation and the dischargingoperation are referred to as a filling position, a dispensing position,a sucking position and a discharging position, respectively.

Next, an example of an operation of recovering a cell which is performedby the dispensing apparatus 100 according to an embodiment of thepresent invention will be described specifically using a flowchart inFIG. 8. It should be noted that, if the cell to be recovered is anadherent cell, the cell is supposed to have been detached in advance bya detachment solution such as trypsin, and thereafter a medium withserum is poured into the dish 5 to stop a detachment action and the cellresults in a state of floating in the medium, being nearly detached andlightly attached, or being deposited on and adhered to the bottomsurface of the dish 5. Whereas, if the cell to be recovered is afloating cell, the cell is supposed to be floating in a medium or bedeposited on and adhered to the bottom surface of the dish 5.

When the dispensing apparatus 100 starts operating (S11), first, thecontrol unit 2 drives the driving portion 8 to cause the dish mountingportion 22 to be tilted toward the syringe 1 at a predetermined angle(S12). Specifically, the control unit 2 drives the fourth servo motor 54to cause the dish mounting portion 22 to rotate on the fourth rotationaxis (dish first axis). A target rotation amount and a target rotationalposition are stored in the storage unit 41 in advance. The control unit2 causes the dish mounting portion 22 to tilt up to a target anglecomparing a detection signal from a rotary potentiometer with a targetrotation amount and a target rotational position stored in the storageunit 41.

Next, the control unit 2 drives the driving portion 8 to direct thenozzle 11 of the syringe 1 to an sucking position which is a second area(S13), and thereafter performs an operation of sucking liquid retainedin the second area containing cells that have been washed off (S14).

The control unit 2 drives the first to third servo motors 51 to 53 inorder to direct the syringe 1 to the second area and causes componentelements of the first to third driving mechanisms 31 to 33 to rotate atpredetermined angles on the first to third rotation axes, respectively.Target rotation amounts or target rotational positions for directing thesyringe 1 to the second area are stored in the storage unit 41 inadvance. The control unit 2 directs the syringe 1 to the second areawhile comparing a detection signal from a rotary potentiometer withtarget rotation amounts and target rotational positions stored in thestorage unit 41.

The present dispensing apparatus 100 is capable of changing thedirection of the nozzle 11 to the first direction and the seconddirection based on the direction of a normal which extends from thenozzle 11 of the syringe 1 to the bottom surface of the dish 5 when thenozzle 11 is directed perpendicularly to the bottom surface, therebybeing able to direct the nozzle 11 to the second area. Then, asillustrated in FIG. 10A, the nozzle 11 of the syringe 1 can be directedto the second area at predetermined angles with respect to the innerbottom surface and the inner side surface of the dish 5 withoutinterference of the nozzle 11 of the syringe 1 with the bottom surfaceand the side surface of the dish 5.

As such, the present dispensing apparatus 100 can suck liquid retainedin the second area of the tilted dish 5.

Further, the present dispensing apparatus 100 causes the syringe 1 tomove in a perpendicularly downward direction by driving the thirddriving mechanism 33 when the nozzle 11 is directed to the second area.It is therefore possible to arrange the tip of the nozzle 11 in adeepest spot in liquid retained in the second area of the tilted dish 5,thereby being able to recover liquid which has flown down to the secondarea without leaving the liquid behind therein.

In the sucking operation, under control by the control unit 2, the pumpP1 is stopped while the pump P2 is driven to open the valve 2 in a statewhere the valve V1 is closed, and using pressure (negative pressure)generated in the pump P2, liquid retained in the second area of the dish5 is sucked from the nozzle 11 of the syringe 1 (pump driven suction).

Next, in the dispensing apparatus 100, the control unit 2 drives thedriving portion 8 to direct the nozzle 11 to a dispensing position (S15)based on the direction of a normal extending from the nozzle 11 of thesyringe 1 to the bottom surface of the dish 5 when the nozzle 11 isdirected perpendicularly to the bottom surface, thereby performing adispensing operation (S16).

The dispensing position is a predetermined position within a ring-shapedarea in which the inner bottom surface of the tilted dish 5 is incontact with the inner side surface thereof, for example.

The dispensing position will be described with reference to FIG. 9 andFIG. 10. FIG. 9 is a diagram exemplifying dispensing positions when thedish 5 mounted on the tilted dish mounting portion 22 is viewed from anegative side to a positive side in the X axis direction and viewed froma negative side to a positive side in the Y axis direction.

FIG. 10A is a diagram when the dish 5 mounted on the tilted dishmounting portion 22 is viewed from a negative side to a positive side inthe Y axis direction, and illustrating respective directions of thenozzle 11 when dispensing positions of the nozzle are in the first areaand the second area. FIG. 10B is a diagram when the dish 5 mounted onthe tilted dish mounting portion 22 is viewed from a direction parallelto the bottom surface of the dish 5, and illustrating respectivedirections of the nozzle 11 when dispensing positions of the nozzle arein the first area and the second area.

A dispensing position when performing the dispensing operation in apresent embodiment is the first area illustrated in FIG. 9 in thevicinity of the uppermost part in a ring-shaped area in which the innerbottom surface of the tilted dish 5 is in contact with the inner sidesurface thereof.

The control unit 2 drives the first to third servo motors 51 to 53 tocause component elements of the first to third driving mechanisms 31 to33 to rotate at predetermined angles on the first to third rotationaxes, respectively, in order to direct the syringe 1 to the first area.Target rotation amounts and target rotational positions are stored inthe storage unit 41 in advance. The control unit 2 directs the syringe 1to the first area comparing a detection signal from a rotarypotentiometer with target rotations and target rotational positionsstored in the storage unit 41.

In the present dispensing apparatus 100, the nozzle 1 can be directed tothe first area by changing the direction of the nozzle 11 in the firstdirection and the second direction based on the direction of a normalextending from the nozzle 11 of the syringe 1 to the bottom surface ofthe dish 5 when the nozzle 11 is directed perpendicularly to the bottomsurface of the dish 5, thereby, as illustrated in FIG. 10A, being ableto direct the nozzle 11 of the syringe 1 to the first area atpredetermined angles with respect to the inner bottom surface and theinner side surface of the dish 5, without interference of the nozzle 11with the bottom surface and the side surface of the dish 5.

Return to FIG. 8, in the dispensing operation (S16), under control bythe control unit 2, the pump P2 is stopped while the pump P1 is drivento open the valve V1 in a state where the valve V2 is closed, usingpressure generated in the pump P1, liquid retained in the syringe 1 isdischarged (pump driven discharge).

With respect to the amount of liquid to be discharged from the syringe 1in the dispensing operation, the relationship between the time to drivethe pumps and the amount to be discharged is defined in advance. Thestorage unit 41 stores data indicative of this relationship, and thecontrol unit 2 controls the valves V1 and V2 and the pumps P1 and P2 sothat a predetermined amount of liquid is discharged from the syringe 1.

As such, it becomes possible in the present dispensing apparatus 100 todirectly pour liquid discharged with pressure from the nozzle 11 of thesyringe 1 toward the above first area of the dish 5. Liquid which hasbeen discharged directly toward the first area flows down whilespreading over the inner bottom surface of the dish 5. It is thereforepossible to effectively wash away cells that are lightly attached oradhered to the inner bottom surface of the dish 5.

Furthermore, in the dispensing apparatus 100 according to an embodimentof the present invention, when the dispensing operation is executed, thecontrol unit 2 drives the driving portion 8 to cause the dish mountingportion 22 to rotate on a rotation axis passing through the center ofthe bottom surface of the dish 5 and perpendicular to the bottomsurface.

As a result, liquid can be thus discharged while rotating the dish 5,thereby being able to directly pour liquid, discharged with pressurefrom the nozzle 11 of the syringe 1 to the first area, over thecircumference of the inner bottom surface of the dish 5. Thus, itbecomes possible to effectively wash off cells that are lightly attachedor adhered to the inner bottom surface of the dish 5.

When a predetermined amount of liquid is discharged from the syringe 1,the control unit 2 performs control such that the above describedrotation of the dish mounting portion 22 is stopped and discharging ofliquid from the syringe 1 is stopped.

The dispensing apparatus 100 performs a dispensing finishing operation(S17). In the dispensing finishing operation, in order to prevent thenozzle 11 of the syringe 1 from dripping droplets and bubbles, forexample, the control unit 2 drives the driving portion 8 to bring thetip of the nozzle 11 into contact with the inner side surface of thedish 5, for example, thereby removing droplets and babbles at the tip ofthe nozzle 11.

When the dispensing finishing operation is ended, a predetermined amountof liquid discharged from the syringe 1 is retained in the second areaof the dish 5 as illustrated in FIG. 9. The second area is an area inthe vicinity of the lowermost part out of an area in which the innerbottom surface of the dish 5 mounted on the tilted dish mounting portion22 is in contact with the inner side surface thereof.

Next, the control unit 2 drives the driving portion 8 while dischargingof liquid from the syringe 1 is stopped, and directs the nozzle 11 ofthe syringe 1 to the second area (S18), and thereafter an operation isperformed of sucking liquid retained in the second area containing cellsthat have been washed off (S19).

In order to direct the syringe 1 to the second area, the control unit 2drives the first to third servo motors 51 to 53 to rotate the componentelements of the first to third driving mechanisms 31 to 33 to rotate atpredetermined angles on the first to third rotation axes, respectively.Target rotation amounts and target rotational positions for directingthe syringe 1 to the second area are stored in the storage unit 41 inadvance. The control unit 2 directs the syringe 1 to the second areacomparing a detection signal from a rotary potentiometer with targetrotation amounts and target rotational positions stored in the storageunit 41.

In the present dispensing apparatus 100, the nozzle 11 of the syringe 1can be directed to the second area, by changing the direction of thenozzle 11 to the first direction and the second direction based on thedirection of a normal extending from the nozzle 11 to the bottom surfaceof the dish 5 when the nozzle 11 is directed perpendicularly to thebottom surface, thereby, as illustrated in FIG. 10A, being able todirect the nozzle 11 of the syringe 1 to the second area atpredetermined angles with respect to the inner bottom surface and theinner side surface of the dish 5, respectively, without interference ofthe nozzle 11 with the bottom surface and the side surface of the dish5.

As such, in the present dispensing apparatus 100, liquid retained in thesecond area of the tilted dish 5 can be sucked.

Further, in the present dispensing apparatus 100, the syringe 1 is movedin a perpendicularly downward direction by driving the third drivingmechanism 33 when the nozzle 11 is directed to the second area. Thus,the tip of the nozzle 11 can be arranged in the deepest spot in liquidretained in the second area of the tilted dish 5, thereby being able torecover liquid which has flown down to the second area without leavingthe liquid behind therein.

In the sucking operation, under control by the control unit 2, the pumpP1 is stopped while the pump 2 is driven to open the valve V2 in a statewhere the valve V1 is closed, and using pressure (negative pressure)generated in the pump P2, liquid retained in the second area of the dish5 is sucked from the nozzle 11 of the syringe 1 (pump driven suction).

The dispensing apparatus 100 executes the above described process fromS15 to S19 the predetermined number of times, i.e., three to five timesin a present embodiment (S20). If the predetermined number of times isset at twice or more, the dispensing apparatus 100 executes the abovedescribed process from S15 to S19 until the number of times the processfrom S15 to S19 is executed reaches the predetermined number of times.By executing the process from S15 to S19 several times, it becomespossible to recover more cells more reliably, when recovering cellslightly attached or adhered to the inner bottom surface of the dish 5.

In the dispensing apparatus 100, when the process from S15 to S19 isexecuted the predetermined number of times (S20; Yes), the control unit2 drives the driving portion 8 to move the syringe 1 to an dischargingposition (S21) in order to perform a discharging operation in whichliquid sucked the last time is dispensed in the storage tank 7 (S22).That is, sucked cells are recovered in the tank.

The discharging position is a position at which liquid is dischargedfrom the nozzle 11 provided in a predetermined location.

The control unit 2 drives the first to third servo motors 51 to 53 torotate the components elements of the first to third driving mechanism31 to 33 at predetermined angles on the first to third rotation axes,respectively, in order to move the syringe 1 to the dischargingposition. Target rotation amounts and target rotational positions formoving the syringe 1 to the discharging position are stored in thestorage unit 41 in advance. The control unit 2 causes the syringe 1 tomove to the discharging position comparing a detection signal from arotary potentiometer to target rotation amounts and target rotationalpositions stored in the storage unit 41.

In the discharging operation, similarly to the dispensing operation,under control by the control unit 2, a pump driven discharge isperformed, and using pressure generated in the pump P1, liquid, whichhas been sucked from the second area of the dish 5 into the syringe 1and contains cells, is discharged into the storage tank 7 (pump drivendischarge).

In the discharging operation, it is desirable to take some measures toprevent the surrounding from being contaminated by the pump drivendischarge, such as emitting liquid while deeply inserting the nozzle 11into the storage tank 7 having enough depth, and bringing the tip of thenozzle 11 into contact with the inner wall of the storage tank 7.

The control unit 2 then determines if the discharging operations of S21and S22, i.e., the recovering process, are executed the predeterminednumber of times or twice to three times in a present embodiment (S23),and when it reaches the predetermined number of times, a series of thesequences is ended (S26).

On the other hand, when it does not reach the predetermined number oftimes (S23; No), the control unit 2 drives the driving portion 8 to movethe syringe 1 to a filling position (position at which the nozzle 11 ofthe syringe 1 is in liquid stored in the reservoir 6 in FIG. 7) (S24)and a filling operation is performed (S25).

In the filling operation, under control by the control unit 2, the pumpP1 is stopped while the pump P2 is driven to open the valve V2 in astate where the valve V1 is closed, and using pressure (negativepressure) generated in the pump P2, new liquid (e.g., medium) is suckedinto the syringe 1 (pump driven suction). When a predetermined amounthas been sucked, the pump P2 is stopped to close the valve V2.

Then, returning to the step S15, the control unit 2 executes the processfrom S15 to S19 the predetermined number of times again. In this case,pouring (dispensing) and sucking are repeated using, e.g., a medium,which is fresh and newly filled from the reservoir 6. As such, inaddition to pouring and sucking using the original medium, pouring andsucking using the new medium are further executed, thereby being able torecover cells more reliably. In an embodiment of the present invention,the process is repeated the number of times obtained by (thepredetermined number of times of S20)×(the predetermined number of timesof S23).

As described above, according to the dispensing apparatus 100 in anembodiment of the present invention, it becomes possible to directlypour liquid discharged from the nozzle 11 of the syringe 1 to any areasincluding peripheral portions in the inner bottom surface of the dish 5.

Therefore, for example, in the process of recovering cells from the dish5, more cells that are lightly attached or adhered to the bottom of thedish 5 can be washed away, thereby being able to improve cell recoveryefficiency. Further, a sufficient amount of liquid to wash off cells canbe directly poured, for a predetermined period of time with apredetermined flow rate, onto such cells that are difficult to berecovered only by flow of liquid flowing down and dispensation of liquidfor a short period of time, such as cells that are nearly detached bydetachment solution such as trypsin and cells that are deposited on andadhered to the bottom surface of the dish, thereby improving therecovery rate.

As an example, a case of a general-sized dish is considered which isusually called a 100-mm dish. An inner bottom portion of the 100-mm dishis about 90 [mm] in diameter.

When areas on which discharged liquid could not be directly poured bythe conventional devices are estimated to be a ring-shaped area of about5 [mm] in the circumference of the inner bottom portion, an area onwhich discharged liquid could directly poured by the conventionaldevices was considered to be only an area of 40 [mm]×40 [mm]×3.14=5024.0[mm2].

In the present dispensing apparatus 100, discharged liquid can be poureddirectly over the entire inner bottom surface, and therefore dischargedliquid can be directly poured on an area of 45 [mm]×45 [mm]×3.14=6358.5[mm2].

When comparing between the above areas, 6358.5 [mm2]/5024.0 [mm2]=1.27is obtained, and thus efficiency improvement of about 27 [%] can berealized.

In the dispensing apparatus 100 according to an embodiment of thepresent invention, as illustrated in FIG. 9 and FIG. 10, when liquid isdischarged from the nozzle 11 of the syringe 1, the nozzle 11 of thesyringe 1 is directed to an area (first area) in the vicinity of theuppermost part in a ring-shaped area in which the inner bottom surfaceof the tilted dish 5 is in contact with the inner side surface thereof.Thus, liquid, which has been directly discharged from the nozzle 11 ofthe syringe 1 to the above first area, flows down, while spreading overthe inner bottom surface of the dish 5, thereby being able toefficiently recover cells that are lightly attached or adhered to theinner bottom surface of the dish 5.

Further, it is also possible to rotate the dish mounting portion 22 on arotation axis passing through the center of the bottom surface of thedish 5 and perpendicular to the bottom surface when liquid is dischargedfrom the nozzle 11 of the syringe 1. That is, the dish mounting portion22 is rotated along a plane parallel to the bottom surface of the dish5. This enables discharging of liquid while rotating the dish 5, therebybeing able to directly pour liquid, which has been discharged from thenozzle 11 of the syringe 1 to the above first area, over thecircumference of the inner bottom surface of the dish 5. Further, inthis case, due to a synergistic effect of the flow of liquid dischargedfrom the nozzle 11 and the rotational speed of the dish 5, the flowvelocity of liquid is increased on the inner bottom surface of the dish5, thereby being able to more efficiently recover cells that are lightlyattached or adhered to the dish 5.

When the dish mounting portion 22 is rotated, the dish mounting portion22 may make one or more rotations in the same direction, for example.This enables directly pouring liquid throughout the entire circumferenceof the above ring-shaped area of the dish 5.

Alternatively, when the dish mounting portion 22 is rotated, the dishmounting portion 22 maybe rotated in the same direction and a reversedirection in an alternate manner. For example, the dish mounting portion22 may be rotated in the reverse direction every other rotation or maybe rotated in the reverse direction every other half rotation. This alsoenables directly pouring of liquid throughout the entire circumferenceof the above ring-shaped area of the dish 5. Moreover, particularly, bychanging the direction of rotation, liquid discharged from the nozzle 11can be poured down from a different direction depending on a rotationaldirection when the liquid is poured down on the dish 5, thereby beingable to further improve an effect of recovering cells that are lightlyattached or adhered to the dish.

Further, when liquid is discharged from the nozzle 11 of the syringe 1,the direction of the nozzle 11 may be moved from the area in thevicinity of the uppermost part (first area) to the area in the vicinityof the lowermost part (second area) in the ring-shaped area in which theinner bottom surface of the tilted dish 5 is in contact with the innerside surface thereof. This causes liquid which has been discharged fromthe nozzle 11 of the syringe 1 directly to the above first area to flowdown while spreading over the inner bottom surface of the dish 5, aswell as the nozzle 11 is moved toward the second area, thereby beingable to directly pour liquid to an area on the moving route.Furthermore, in this case, the direction of the nozzle 11 may becombined with a direction in which two areas (third area and fourtharea) are connected that oppose to each other in the parallel directionin the ring-shaped area where the inner bottom surface of the tilteddish 5 is in contact with the inner side surface thereof.

Further, when liquid is discharged from the nozzle 11 of the syringe 1,the direction of the nozzle 11 may be moved to up and down directionswhile being changed alternately to left and right directions (seconddirection) so as to scan the entire inner bottom surface of the dish 5.This can cause liquid discharged from the nozzle 11 of the syringe 1 toflow down while spreading over the inner bottom surface of the dish 5,as well as cause liquid to be directly poured to a wide area on theroute to move the nozzle 11. In this case, the direction of the nozzle11 may be moved after the dish mounting portion 22 has been fixed. Thismakes it possible to omit the fifth driving mechanism 35, for example,since rotation of the dish mounting portion 22 is not required.

Furthermore, when performing the dispensing operation, for example, thenozzle 11 of the syringe 1 may be initially directed to the second areaillustrated in FIG. 9 (area in the vicinity of the lowermost part in thering-shaped area in which the inner bottom surface of the tilted dish 5is in contact with the inner side surface thereof), and then is directaround along the ring-shaped area in which the inner bottom surface ofthe dish 5 is in contact with the inner side surface thereof. This makesit possible to omit the fifth driving mechanism 35, for example, sincerotation of the dish mounting portion 22 is not required.

The above embodiments of the present invention are simply forfacilitating the understanding of the present invention and are not inany way to be construed as limiting the present invention. The presentinvention may variously be changed or altered without departing from itsspirit and encompass equivalents thereof.

1. A dispensing apparatus comprising: a dish mounting portion having amounting surface mounted with a dish having a bottom surface and a sidesurface surrounding the bottom surface; a syringe, arranged above thedish mounting portion, having a nozzle configured to discharge liquidtoward an interior of the dish; and a first driving portion configuredto change the syringe in direction with respect to a first axis as acenter, wherein the first axis is orthogonal to a normal to the mountingsurface of the dish mounting portion.
 2. The dispensing apparatusaccording to claim 1, further comprising a second driving portionconfigured to change the syringe in direction with respect to a secondaxis as a center, wherein the second axis is orthogonal to the normal aswell as perpendicular to the first axis.
 3. The dispensing apparatusaccording to claim 2, further comprising a third driving portionconfigured to move the syringe in a direction toward and away from thedish mounting portion.
 4. The dispensing apparatus according to claim 3,further comprising a fourth driving portion configured to change adirection of an inner bottom surface of the dish mounted on the dishmounting portion so as to be in a state tilted toward the syringe and ahorizontal state with respect to a dish first axis as a center, whereinthe dish first axis is parallel to the first axis.
 5. The dispensingapparatus according to claim 4, further comprising a fifth drivingportion configured to cause the dish mounting portion to rotate along aplane parallel to the inner bottom surface of the dish mounted on thedish mounting portion with respect to a dish second axis as a center,wherein the dish second axis is perpendicular to the dish first axis.